doi: 10.3752/cjai.2015.28
http://zoobank.org/References/1360ED3A-8330-43BD-B051-2DDBBBD76AA0
C. Taxonomic treatment
15. Xeris umbra Goulet, n. sp.
Fig. C15.1 (female habitus)
Fig. C15.2 (male habitus)
Holotype. Female (OLML), in good condition except for five apical flagellomeres on left antenna missing, labelled [White] “China, Yunnan prov. 1.-19.7.1992 Heishui 35 km N of Lijiang 27, 13 N 100, 19 E Lgt. S.Becvar”; [White] “LI egg. 1992/93ex Coll.j.Halada”; [Red] “HOLOTYPE Xeris umbra ♀ H. Goulet, 2015”.
Paratypes. (6 males). CHINA: Yannan, Heishui 35 km N of Lijiang 27, 13 N 100,19 E (2 M, OLML); Yunnan, 25 km E Zhongdian 22.6.1998 3500 m Leg. S. Muzin (3 M, OLML); Yunnan, Yulongshan Mts. 3500-4000m 27.10N 100.13E 16-19/6. 1993 Vίt Kubàň (1 M, OLML).
Among specimens with a yellowish-white fore wing cell C cell and with vertex bearing less dense pits (usually not touching) and finer pits (0.05–0.25 times of lateral ocellus) between the eye dorsal edge and the occiput outside postocellar area [umbra, malaisei, pallicoxae, spectrum, xanthoceros and xylocola], X. umbra is recognized in both sexes by the long setae on the clypeus (setae 1.0–1.4 times as long as length of lateral ocellus) and the very fine and poorly outlined pits on metanotum posterior to cenchrus and laterally on metascutellum, and in females by the small teeth on the apical 0.3 of cornus.
FEMALE
Color. Head black except for white spot (rarely missing) on gena dorsal to middle of eye; white spot often not clearly outlined and small, and with ventral edge not extending to genal ridge (Fig. C15.3); antenna black; last maxillary palpomere black (Fig. C15.3). Thorax black (Fig. C15.1). Legs with coxae, trochanters, basal 0.8 of femora black, and apical 0.5 of tarsomeres 1 black, tarsomeres 2–5 brown; apical 0.2 of femora, tibiae and basal 0.5 of tarsomeres 1 light reddish brown (Fig. B2.106 and Fig. C15.1). Fore wing clear except for lightly tinted band in apical 0.25, and along a central band outlined by cells 2CU, 3CU, 1M and 1R1 (as in Fig. B2.67); cell C very light yellow (paler in old specimens) (as in Fig. B2.40); most of area ventral to anal cells yellowish brown; veins black but white at base of stigma on both sides of junction with vein 1r-rs (as in Fig. B2.40). Abdomen black (Fig. C15.1). Sheath with apical section black and basal section reddish brown.
Head. Distance between nearest eye edge and lateral ocellus edge about 1.5 times as long as distance between inner edges of lateral ocelli (as in Fig. B2.20). Setae on clypeus setae 1.0–1.4 times as long as length of lateral ocellus (Fig. B2.102 and Fig. C15.3). Eye in lateral view (N = 1) with its maximum height 1.5 times as long as its maximum length (Figs. B2.102 and Fig. C15.3), and maximum height of eye 0.46 times as long as maximum height of head (from transverse ridge on gena above mandible to top of head (Fig. B2.102), measurements as in Fig. B2.8). Gena in dorsal view with maximum distance between outer edges clearly wider than maximum distance between outer edges of eyes (as in Fig. B2.43), in frontal view outer edges of eyes clearly not intersecting genae (as in Fig. B2.5); in lateral view with distance between outer edge of eye and genal ridge 0.4 times as long as maximum length of eye (Figs. B2.102 and Fig. C15.3), measurements as in Fig. B2.77), with few or no pits ventral to genal ridge, and with many small size pits (diameter of pit 0.1 times lateral ocellus diameter) between outer edge of eye and genal ridge (mainly near eye) (Figs. B2.102 and Fig. C15.3). Transverse ridge above mandible narrow, sharp and mainly smooth (Fig. C15.3). Vertex scarcely pitted and pits medium in size (diameter of pits 0.2–0.4 times lateral ocellus diameter) (as in Fig. B2.43); pits present from dorsoposterior edge of eye to occiput outside postocellar area, absent on most of postocellar area, pits dense medium in size along all of shallowly outlined and gutter-like median furrow but a little more widespread near lateral ocelli (as in Fig. B2.43).
Thorax. Pronotum in dorsal view along lateral margin with irregular ridges between large teeth (as in Fig. B2.95) and with a wide shiny surface medially, surface widest anteriorly with a deep impression behind middle (as in Fig. B2.134, insert); in lateral view with coarse polygonal pits on 0.5 of posterior surface (as in Fig. B2.97). Propleuron in lateral view with small polygonal pits over most of surface (as in Fig. C12.7); in ventral view generally with dense teeth often forming shallow pits with shallowly impressed meshed of microsculpture in between (Fig. B2.22). Transcutal furrow of mesonotum obscured by coarse pits, thus mesoscutum and axilla apparently fused (Fig. C15.5). Metanotum with surface posterior to cenchrus and lateral 0.5 of metascutellum finely pitted (pit 0.1 times as wide as diameter of lateral ocellus) (Fig. B2.104). Fore wing in middle 0.3 of vein 2A diverging considerably (as in Fig. C12.6) away from wing edge, and then less (as in Fig. C12.6) abruptly curved away from wing edge; vein 3A absent.
Abdomen. Tergum 8 on central area consisting mainly of partly fused and flat sculpticells forming transverse lines of various lengths, pitted sculpticells uncommon medially and not so deep (Fig. C15.6), and lateral margin shiny on apical 0.5 (as in Fig. B2.141, insert). Tergum 9 with meshes of microsculpture on ventral half below longitudinal furrow near center impressed and sculpticells mainly flat, meshes above longitudinal furrow near center well impressed and sculpticells clearly scale-like (as in Fig. B2.92, insert); median basin with base (outlined by two lateral black longitudinal furrows; N = 1) 0.85 times as wide as its median length, with maximum width of basin 1.3 times as wide as its median length and basin 0.45 times as long medially as median length of cornus (measurements as in Fig. A3.2). Cornus constricted in dorsal view, its minimum width (at constriction) about 0.8 times as wide as maximum width subapically (as in Fig. C1.15); with small teeth in apical 0.3 (Fig. B2.109). Sheath. Basal section 0.36 times as long as apical section (N = 1) (Fig. C15.1); lateral surface of apical section with well-defined ridge (as in Fig. B2.13, insert); length 1.2 times as long as fore wing length. Ovipositor. Lancet with annuli beyond 7 missing; junction of basal and apical sections of sheath aligned between 3rd and 4th annuli; apical section of ovipositor missing, probably major pits present on last 4–5 apical annuli before teeth annuli, and with small to very small pit on all or almost all of preceding annuli up to annulus 5 (as in Fig. C1.18).
MALE
Color. Head with dorsal spot behind eye clearly outlined, larger in size than spot in female, and extending to genal ridge (Fig. C15.4). Pronotum dorsally completely black, or black with anterolateral corner yellowish white, or black with anterolateral corner yellowish white extended toward posterolateral corner, or black with yellowish-white band extending to posterolateral corner; anterior vertical surface below anterolateral corner with a black, or brown, or white spot (as in Figs. B2.57, B2.54, B2.55, B2.58). Legs black, or with basal 0.1 of tibiae clearly yellowish white. (Figs. B2.111 and C15.2). Fore wing almost completely clear except for a light tint around the junction of veins Cu and 2cu-a and cell 1R1 (Fig. C15.2).
Thorax. Metatibia with a shallow to deep notch on dorsal edge in basal 0.25 (C15.2).
Adults of X. umbra are the darkest specimens of Xeris. They are easily distinguished on color pattern and some structural features from all other species of Xeris. They are related to the X. spectrum lineage as shown by the presence of a very small pit on each of the most basal annuli.
The specific name “umbra” is a noun in apposition meaning “shadow” referring to the very dark color pattern of both sexes.
CHINA, Yunnan.
MALE
Color. Head with dorsal spot behind eye clearly outlined, larger than in female, and extending to genal ridge (Fig. C11.4). Coxae black; trochanter partly to completely reddish brown; femora reddish brown to black; tibiae whitish yellow in basal 0.3 and sharply outlined, protibia light reddish brown with a wide longitudinal band on outer margin in apical 0.5 or with black transverse band in apical 0.5, mesotibia light reddish brown with black transverse band in apical 0.6, and metatibia except at base black; tarsi light reddish brown except for black dorsal longitudinal band on mesotarsomere 2 (rarely all black) (Figs. B2.101 and C11.2); metatarsomere 1 yellowish white at base and narrowly reddish brown at apex (rarely black on pro- and mesotarsomeres 2 and almost never on tarsomeres 3), and with brown or black central transverse band or cloud on metatarsomere 2 in most specimens. (Figs. B2.101 and C11.2).
Thorax. Metatibia with shallow notch on dorsal edge in basal 0.25 (Figs. B2.101 and C11.2).
We were surprised to uncover an undescribed European species under X. spectrum. This was the result of a detailed study of the American species known traditionally as X. spectrum spectrum, (see “Taxonomic notes” under X. caudatus). Females of X. pallicoxae are separated from those of X. spectrum on color of coxae, and on the absence of a small pit on each of the annuli anterior to the typical group of subapical annuli with larger pit, males on the color pattern of mesotarsomere 1 and metatarsomere 1, and both sexes on the lack or almost lack of coarse pits on the vertical surface of the pronotum in lateral view, on the sculpture on the lateral surface of the propleuron and on the lack of microsculpture between large teeth along the longitudinal yellowish-white band on the pronotum.
When everything looks straight forward, complications show up. The DNA barcode neighbor-joining tree of X. pallicoxae may consist of two species named here “Type 1” and “Type 2” (see Figs. D1.2e and discussion under “Mitochondrial DNA results”). The sequences are based on larvae (USNM) and there is a divergence of 2.2% between the two groups of DNA barcodes. In the analysis of the main emergence cycle of X. pallicoxae we noted the unusual two adult emergence peaks one in early June and another in late June (see Fig. C11.9). Normally a species emergence consists of one peak over a one month period in studied Siricidae (Schiff et al., 2012). Therefore, the two peaks in adult emergence is a clue supporting the DNA barcode results. We are unable to assign the name X. pallicoxae to either type as the data is based on larvae. Fresh adults for barcoding are needed to associate them with the larval barcodes and eventually find morphological differences to distinguish the adults.
The specific name “pallicoxae” means “pale coxae” characteristic of females of this European species.
We noted no geographical differences among females of Xeris pallicoxae over its range. However, males show a pattern. The metafemur color varies from reddish brown to black. In Central Europe and on the island of Corsica (France) a black metafemur is the dominant color. Elsewhere between France and Turkey in the Mediterranean region, a reddish-brown metafemur dominates. In Italy, specimens with intermediate color pattern are common. However at the extreme eastern portion of the X. pallicoxae range in Turkey, specimens with intermediate color pattern are uncommon.
We studied 822 specimens (BMNH) of X. pallicoxae collected by P. J. Spradbery and A. A. Kirk between 1963 and 1970. Each specimen’s label includes the name “Frank Wilson” who did not collect the specimen but supervised the rearing program sponsored by the Australian government. This is only a portion of about 4000 specimens collected by them.
The published result of the emergence period and the host range (Spradbery and Kirk 1978) is a mixture of specimens of X. pallicoxae and X. spectrum. Their emergence period was based on specimens from Turini in southeastern France. We saw about 35% (87 specimens) of their Turini sample. This sample consists of 79% X. pallicoxae and 21% X. spectrum. Comparing results of the emergence distribution from Central Europe with that from Mediterranean Europe including Turkey, we found that emergence starts in mid-May along the Mediterranean region and in late May in Central Europe. In both regions there are two clear emergence peaks in spring. Based on 571 specimens, the first peak occurs in the first week of June and the second in the last week of June (Fig. C11.9). The major emergence period is followed by a very small emergence in late September and early October. These results are similar over the years, but there could be a general shift of one week either way. In contrast, Xeris spectrum shows only one emergence period, with a single peak in late June.
One sample from Hampshire, England, collected from a Larix bole was unusual because of the size difference between specimens emerged from the first and second year after the tree was cut down. Specimens from the first year (N = 40 males) were clearly smaller than those of the second year (N = 27 males). The maximum head width in dorsal view was 2.7 mm (standard deviation = 0.22; range 2.1–3.2 mm) for the first year and 3.7 mm (standard deviation = 0.35; range 2.1–4.2 mm) for the second year. Four specimens from the second year were well within the range of those of the first year sample (2.1–3.0) whereas all other specimens were greater than 3.3 mm. Xeris females do not carry fungi within their reduced mycangia. Therefore, a possible hypothesis is that specimens of X. pallicoxae from the first year sample were in competition for the fungus (brought previously by females of Urocerus and/or Sirex) with larvae of Urocerus and/or Sirex, whereas those of the second year with lower numbers of larvae would have most of the fungus to themselves.
Xeris pallicoxae has a moderately wide host range within Pinaceae. Based on 20% of specimens at the BNMH (162) collected by Spradbery and Kirk, X. pallicoxae was reared from a wide variety of firs (Abies alba, A. borisii-regis, A. cilicica, and A. bornmuelleriana), spruce (Picea abies) and and Pine (Pinus radiata). Spradbery and Kirk (1978) reported X. spectrum from A. equi-trojan in Greece where we have seen only X. pallicoxae. Amazingly, 97% of specimens were reared from firs. This may reflect a relatively greater abundance of firs than spruces in sites sampled by Spradbery and Kirk rather than a marked preference of X. pallicoxae for firs. Spruces are very uncommon in the Mediterranean region based on their known distribution and their sample’s host data (Spradbery and Kirk 1978).
EUROPE: AUSTRIA, BELGIUM, BULGARIA, CZECH REPUBLIC, CROATIA, DENMARK, FRANCE (continental), FRANCE (Corsica), GERMANY, GREECE, HUNGARY, ITALY, NETHERLANDS, NORWAY, POLAND, ROMANIA, SLOVAKIA, SWITZERLAND, TURKEY, UNITED KINGDOM, and YUGOSLAVIA. Xeris pallicoxae is a widespread European species from Denmark and Poland south to Italy and from France to Turkey, and most captured specimens south of Germany belong to this species.
Numerous specimens of Xeris pallicoxae have been intercepted at ports in the United States (22) and New Zealand (27) from the following European countries: Denmark (New Zealand), France (United States and New Zealand), Germany (United States, New Zealand and Puerto Rico), Italy (United States), Romania (United States), Switzerland (New Zealand), and Yugoslavia (New Zealand). The species is not established outside Europe.
Specimens studied: 314 females and 603 males from BMNH, CNC, EIHU, SDEI, SDEI – Col. E. Jansen, and USNM.
Specimens for molecular studies: 21 specimens. See Fig. D1.2e. For each specimen the following is recorded: country, year, state/province, specimen code (in italics), and number of base pairs.
EUROPE. Austria: S516, 631. Belgium: 1975, S65, 658. France: 1978, S293, 658; 1977, S497, 658. Germany: 1979, S68, 658; 1977, S473, 658; 1978, S179, 658; 1978, S198, 658; 1977, S269, 658; 1978, S296, 658; 1977, S344, 658; 1977, S347, 658; 1978, S394, 658; 1978, S426, 658; 1981, S442, 658; 1977, S474, 658; 1977, S487, 658. Italy: 1971, S76, 658; 1972, S82, 658; 1973, S126, 658; 1977, S264, 658.
